Use of development inhibitor releasing compounds in photothermographic elements

ABSTRACT

A SILVER HALIDE DEVELOPMENT INHIBITOR RELEASING COMPOUND, SUCH AS A DEVELOPING AGENT OR COUPLER CONTAINING A DEVELOPMENT INHIBITOR MOIETY WHICH IS RELEASABLE UPON HEATING, IN A PHOTOGRAPHIC AND THERMOSENSITIVE ELEMENT SUITABLE FOR DRY PROCESSING, PROVIDES IMPROVED BLACK TONE, REDUCED BACKGROUND PRINT-OUT, IMPROVED IMAGE STABILITY, AND REDUCTION OF EXPOSURE AND PROCESSING TIME IN SOME CASES. A COMBINATION OF A SILVER HALIDE DEVELOPMENT INHIBITOR RELEASING COMPOUND, SUCH AS ONE CONTAINING A HEAT RELEASABLE PHENYLMERCAPTOTETRAZOLE GROUP, IN COMBINATION WITH A STABLE SOURCE OF SILVER FOR PHYSICAL DEVELOPMNET ARE USEFUL IN PHOTOGRAPHIC ELEMENTS FOR DRY PROCESSING. THE ELEMENT CAN CONTAIN A SENSITIZING DYE AND A STABLE DEVELOPED IMAGE CAN BE PROVIDED BY HEATING THE ELEMENT AFTER EXPOSURE. THE PHOTOGRAPHIC COMPONENT CAN BE PHOTOGRAPHIC SILVER HALIDE, OR OTHER SUITABLE PHOTOGRAPHIC METAL SALTS.

United States Patent Oflice 3,700,457 Patented Oct, 24, 1972 U.S. Cl.96--114.1 15 Claims ABSTRACT OF THE DISCLOSURE A silver halidedevelopment inhibitor releasing compound, such as a developing agent orcoupler containing a development inhibitor moiety which is releasableupon heating, in a photographic and thermosensitive element suitable fordry processing, provides improved black tone, reduced backgroundprint-out, improved image stability, and reduction of exposure andprocessing time in some cases. A combination of a silver halide development inhibitor releasing compound, such as one containing a heatreleasable phenylmercaptotetrazole group, in combination with a stablesource of silver for physical developmnet are useful in photographicelements for dry processing. The element can contain a sensitizing dyeand a stable developed image can be provided by heating the elementafter exposure. The photographic component can be photographic silverhalide, or other suitable photographic metal salts.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to photographic elements, compositions and processes fordeveloping and stabilizing a latent image using so-called dry processingwith heat. In one of its aspects, it relates to photographic elementssuitable for dry processing with heat containing a silver halidedevelopment inhibitor releasing compound, especially one containing aheat releasable phenylmercaptotetrazole moiety. In another of itsaspects, it relates to a photographic emulsion suitable for dryprocessing with heat containing a silver halide development inhibitorreleasing compound. A further aspect relates to a dry process ofdeveloping and stabilizing an image in a photographic element containinga silver halide development inhibitor releasing compound as described.

Description of the prior art It is known to develop a latent image in aphotographic silver halide element using a silver halide developingagent in so-called dry processing with heat, the photographic elementcan contain a silver halide developing agent as Well as a stabilizercomponent. After exposure, the resulting latent image is developed andstabilized by heating the photographic element. Such a process isdescribed, for example, in U.S. Pat. 3,301,678 of Humphlett et al.issued Jan. 31, 1967.

Other methods of so-called dry processing with heat are described, forexample, in U.S. Pat. 3,152,904 of Sorensen et al. issued Oct. 13, 1964.For example, (1) an organic silver salt which is an oxidizing agent, (2)an organic reducing agent and a low concentration of photographic silverhalide are provided in a light-sensitive element. After image-wiseexposure, the resulting latent image is developed by heating theelement. Methods of this type are also described, for example, in FrenchPat. 1,441,619 and Belgian Pat. 705,872.

Phenylmercaptotetrazole compounds, such as l-phenyl-S-mercaptotetrazole, have been proposed in certain photographic andthermosensitive materials. These compounds can improve the image tone asdescribed in U.S. Pat. 3,257,205 of Cassiers et al. issued June 21,1966. They have been employed in heat developable photographic materialsas described in British Pat. 1,055,144 to improve stability. And,mercaptoazole compounds can be antifoggants, such as described inBritish Pat. 711,025. Unfortunately, phenylmercaptotetrazole presents aproblem because it desensitizes photographic silver compounds atconcentrations which produce stabilization and toning. For example, in aphotographic element suitable for so-called dry processing with heatphenylmercaptotetrazole causes only a faint image to be developed due todesensitization. This is demonstrated in the following Example 4.Accordingly there has been a continuing need for a photographic elementsuitable for so-called dry processing with heat which has improvedstability, including reduced background print-out upon exposure to lightafter processing, improved black tone, increased sensitivity includingreduced exposure and processing time and improved preprocessing spectralsensitivity when a spectral sensitizing dye is not employed.

SUMMARY OF THE INVENTION According to the invention, improved stability,including reduced background print-out upon exposure to light afterprocessing, improved black tone and increased sensitivity is provided ina photographic and thermosensitive element, composition and/or processemploying a silver halide development inhibitor releasing compound,especially a compound Which releases a phenylmercaptotetrazole moietyupon heating.

DESCRIPTION OF PREFERRED EMBODIMENTS A range of compounds can beemployed which are silver halide development inhibitor releasingcompounds, especially compounds which release a phenylmercaptotetrazolemoiety upon heating. Any silver halide development inhibitor releasingcompound is suitable which releases a silver halide developmentinhibitor, especially a phenylmercaptotetrazole moiety, upon heating,which provides improved stability, including reduced backgroundprint-out upon exposure to light after processing, does not adverselyaffect the latent image before processing and does not causedesensitization. Typical silver halide development inhibitor releasingcompounds are (1) development inhibitor releasing couplers, also knownas DIR couplers, as described, for example, in U.S. Pat. 3,227,554 ofBarr et al. issued Jan. 4, 1966 and (2) development inhibitor releasingsilver halide developing agents as described, for example, in U.S. Pat.3,379,529 of Porter et al. issued Apr. 23, 1968 and Belgian Patent713,448.

The development inhibitor moiety which is released upon heating isusually a mercaptan. The mercaptan is believed to form a stable silvermercaptide with unexposed silver halide in the photographic element uponheating. But, the mechanism of stabilization and the reasons, inso-called dry processing, for the improved black tone, increasedsensitivity, and in some cases improved preprocessing spectralsensitivity, when a spectral sensitizing dye is not employed, is notfully understood.

Suitable mercapto groups which can be released upon heating include, forexample:

(a) Mercaptoalkylamidobenzothiazoles, such as described in U.S. Patent2,503,861 of Weissberger issued Apr. 11, 1950; (b)mercaptoalkylamidothiazoles, such as described in U.S. Patent 2,657,136of Knott et al. issued Oct. 27, 1953 or U.S. Patent 2,697,099 of Knottissued Dec. 14, 1954; (c) mercaptoazines such as described in U.S.Patent 2,753,027 of Troendly et al. issued Oct. 30, 1951; (d)mercaptoazoles, such as described in U.S.

Patent 2,590,775 of Kendall et al. issued Mar. 25, 1952; U.S. Patent2,668,113 of Schwalenstocker issued Feb. 2, 1954; and U.S. Patent2,566,659 of Fry issued Sept. 4, 1951; (e) mercaptocysteines, such asdescribed in U.S. Patent 2,363,777 of Downing et a1. issued Nov. 28,1944; (f) mercaptoglutathiones, such as described in U.S. Patent2,110,178 of Ruskin issued Mar. 8, 1938; (g) mercaptooxadiazoles, suchas described in U.S. 2,843,- 491 of Hallen et al. issued July 15, 1958;(h) mercaptopyrimidines, such as described in U.S. Patent 2,304,962 ofShepard et al. issued Dec. 15, 1942; U.S. Patent 2,232,707 of Kendallissued Feb. 25, 1941; U.S. Patent 2,231,127 of Kendall issued Feb. 11,1948; and U.S. Patent 2,173,628 of Kendall issued Sept. 19, 1939; (i)mercaptotetrazoles, such as described in U.S. Patent 2,697,040 ofParnell issued Dec. 14, 1954; U.S. Patent 2,465,149 of Dersch et a1.issued Mar. 22, 1949; U.S. Patent 2,453,087 of Dersch et al. issued Nov.2, 1948; and U.S. Patent 2,403,927 of Kendall et al. issued July 16,1946; (j) mercaptothiadiazoles, such as described in U.S. Patent2,743,184 of Kendall issued Apr. 24, 1956; (k) mercaptothiazoles, suchas described in U.S. Patent 2,824,001 of Hallen et al. issued Feb. 18,1958; (l) mercaptothiophenes, such as described in U.S. Patent 2,214,446of Falbers et a1. issued Sept. 10, 1940; and U.S. Patent 1,758,576 ofMattheis et al. issued May 13, 1930; (m) mercaptotriazines, such asdescribed in U.S. Patent 2,476,536 of Dersch issued July 19, 1949.

The mecaptan moiety which is preferred is a S-tetrazolylthio moiety ofthe formula:

(I) N=N wherein R is alkyl, such as alkyl containing 1 to 5 carbonatoms, such as methyl, ethyl, propyl, butyl or pentyl or aryl, such asaryl containing 6 to 20 carbon atoms, such as phenyl, tolyl and xylyl.Alkyl or aryl, as described, can contain a range of substituents whichdo not adversely affect the stabilization desired upon heating, such asalkoxy, e.g. alkoxy containing 1 to 5 carbon atoms, such as methoxy,ethoxy, propoxy, butoxy, and pentoxy; halogen, cyano, nitro, amino,sulfo, sulfamyl, sulfonylphenyl, sulfonylalkyl, sulfonamidophenyl,sulfonamidoalkyl, carboxy, carboxylate, carbamyl, carbamylphenyl andcarbamylalkyl. R is a coupler moiety or silver halide developing agentmoiety.

A range of couplers can be employed which have developer inhibitorreleasing moieties as described. The color coupler portion of thecompound is typically a 5- pyrazolone coupler moiety, a phenolic couplerincluding alpha-naphtho'ls, or an open chained ketomethylene couplermoiety. In color processes such couplers reacting with oxidized colordeveloping agents form magenta, cyan and yellow dyes, respectively.While the present invention can be employed in elements for producing acolor image, such as described in Belgian Patent 705,872 issued Apr. 30,1968, it is preferably employed in a black-and-white process. In thedescribed couplers, the developer inhibitor releasing moiety istypically in the coupling position of such couplers. The S-pyrazolonecoupler radicals couple typically at the carbon atom in the 4 position,the phenolic coupler compounds couple typically at the carbon atom inthe 4 position and the open chained ketomethylene coupler compoundscouple at the carbon atom forming the methylene moiety. The couplers cancontain so-called balasting and solubilizing groups in the practice ofthe invention. Balasting groups are groups which contain a so-calledbulky organic moiety such as an alkyl group or aryl group containingabout 8 to about 22 or more carbon atoms attached to the coupler moiety.Typical solubilizing groups include,

for example, carboxyl, sulfonyl, sulfonamido and bydroxy groups.

Examples of suitable couplers which can be employed in the practice ofthe invention and contain a phenylmercaptotetrazole moiety include:

1-hydroxy-4-( 1-phenyl-5-tetrazolylthio -N- [6- (2,4-ditert-amylphenoxy)butyl] -2-naphthamide 1-hydroxy-4-( 1-phenyl-5-tetrazolylthio-2'-tetradecyloxy-2-naphthanilide 4-( 1-phenyl-5-tetrazolylthio phenol1-hydroxy-4-( l-phenyl-5-tetrazolylthio -3,5"-dicarbomethoxy-Z-naphthanilide 1-hydroxy-4-1-phenyl-5-tetrazolylthi0 -3,5 '-dicarboxy- 2-naphthanilide1-hydroxy-4-( 1-phenyl-5-tetrazolylthio) -N- [18-(3 ,5

dichlorosulfonylbenzamido ethyl] -2-naphthamide 1-hydroxy-4-1-phenyl-5-tetrazolylthio -N- fi- 3,5

disulfobenzamido ethyl] -2-naphthamide dipotassium salt phenyl1-hydroxy-4-( 1-phenyl-5-tetrazolylthio -2- naphthoate 1-hydroxy-4-(1-phenyl-5-tetrazolylthio)-5'-carbomethoxy-2'-methoxy-2-naphthanilide1-hydr0xy-4- l-phenyl-5-tetrazolylthio -4'- (2,4-ditert-amylphenoxy-2-naphthanilide 1-hydroxy-4-( 1-phenyl-5-tetrazolylthio) -2'-(2,4-di-tertamylphenoxy) -5 3,5 -dicarbomethoxyphenylcarbamyl-2-naphthanilide l-hydroxy-4- 1-phenyl-5-tetrazolylthio )-2-2,4-ditert-amylphenoxy -5 3,5 -dicarboxyphenylcarbamyl -2-naphthanilide1-hydroxy-4- 1-phenyl-5-tetrazolylthio -3',5'-dicarbomethoxy-N-octadecyl-Z-naphthanilide 1-phenyl-3-octadecylamino-4- 1-phenyl-5-tetrazolylthio 5-pyrazolone 1- [4-(4-tert-butylphenoxy) phenyl] -3-phenyl-4-( lphenyl-S-tetrazolylthio-5-pyrazolone 1-phenyl-3-pentadecyl-4-( 1-phenyl-S-tetrazolylthio) -5-pyrazolone 1- 4-stearamidophenyl -3-ethoxy-4-(l-phenyl-S-tetrazolylthio) -5-pyrazolone 1- [4- 4-tert-butylphenoxyphenyl -3- a-4-tert-butylphenoxy propionamido -4-(1-phenyl-5-tetrazoly1thio S-pyrazolone l- 4- 4-tert-butylphenoxy)phenyl] -3- [oz- 4-tert-butylphenoxy) propionamido -4- 1-4-carbomethoxyphenyl -5-tetrazolylthio ]-5-pyrazolone1-(2,4-dichloro-6-methoxyphenyl)-3-[a-(3-pentadecylphenoxy acetamido]-4-( l-phenyI-S-tetrazolylthio -5- pyrazolone 1-dodecyl-3- [a-2,4-di-tert-amylphenoxy acetamido] 4-( 1-phenyl-5-tetrazolylthio-5-pyrazolone Y ,4-di-n-amylphenoxy) acetamido] -4-( 1-phenyl-S-tetrazolylthio )-5-pyrazolone1-phenyl-3-benzamido-4-(1-phenyl-S-tetrazolylthio)-5- pyrazolone1-phenyl-3- a- 2,4-di-tert-amylphenoxy acetamido -4-l-phenyl-S-tetrazolylthio -5-pyrazolone 1-phenyl-3- ['y-2,4-di-tert-amylphenoxy butyramido -4-1-phenyl-5-tetrazolylthio)5-pyrazolone 1-phenyl-3-octadecylcarbamyl-4-methyl-4- l-phenyl-S- tetrazolylthio -5-pyraz0lone1- 2,4,6-trichlorophenyl -3-{3- [oc- 2,4-di-tert-amylphenoxy) acetamido]benzamid0}-4- l-phenyl-S-tetra- Zolylthio -5-pyrazolone 1-2,4,6-trichlorophenyl -3-pentadecyl-4- l-phenyl-S- tetrazolylthio-5-pyrazolone a-{ 3- a- 2,4-di-tert-amylphenoxy) acetamido benzoyl}- u-(1-phenyl-5-tetrazolylthio -2-fiuoroacetanilide a-B6I1ZOy1-a[ 1-3-pelargonamidophenyl) -5-tetrazolylthio] acetanilide 1-hydroxy-4-1-phenyl-5-tetrazolylthio)-2-naphthoic acid An especially suitabledeveloper inhibitor releasing coupler is1-hydroxy-4-(1-phenyl-5-tetrazolylthio)-2-(2'-n-tetradecyloxy)-naphthanilide of the formula:

While developer inhibitor releasing couplers are especially suitable inthe practice of the invention, other developer inhibitor releasingcompounds can be employed, such as developer inhibitor releasingdeveloping agents such as (1-phenyl-5-tetrazolylthio) hydroquinonesilver halide developing agents. Such compounds and preparation of thecompounds is described, for example, in U.S. Patent 3,379,529 of Porteret al. issued Apr. 23, 1968. Useful compounds which are silver halidedeveloping agents containing a development inhibitor releasing moietyare compounds of the formula:

wherein X, Y and Z are each hydrogen, alkyl, especially alkyl containing1 to 20 carbon atoms, such as methyl, ethyl, propyl, butyl, octyl,decyl, and eicosyl, hydroxyl, amino, aryl, especially aryl containing 6to 20 carbon atoms, such as phenyl, tolyl and xylyl, halogen, such aschlorine, bromine and iodine, heterocyclic, especiallymercaptotetrazolyl; R is as described; and X and Y can be members of acarbocyclic ring, especially a 6-member carbocyclic ring.

Examples of suitable silver halide developing agents containing adeveloper inhibitor release moiety are:

2-methyl-5-( 1-phenyl-5-tetrazolylthio) hydroquinonel-phenyl-S-tetrazolylthio -trirnethyl hydroquinone 2-n-octadecyl-5-(1-phenyl-5-tetrazolylthio) hydroquinone lphenyl--tetrazolylthio)hydroquinone 2,5 -bis( l-phenyl-S-tetrazolylthio) hydroquinone2-tertbutyl-5- l-phenyl-5-tetrazolylthio) hydroquinone2-(4-methylphenyl)-5-(1-phenyl-5-tetrazolylthio)hydroquinone5,8-ethano-2-(1-phenyl-5-tetrazolylthio)-5,8-dihydro-1,4-naphthohydroquinone2,5-bis-(2-chloroacetoxy)-3-(1-phenyl-5-tetrazolylthio) hydroquinone 2,5-dimethyl-3-( 1-phenyl-5-tetrazolylthio) hydroquinone 2,6-dimethyl-3-(1-phenyl-5-tetrazolylthio) hydroquinone2,3-dimethyl-5-(1-phenyl-5-tetrazolylthio) hydroquinone2-n-pentadecyl-5-( l-phenyl-5-tetrazolylthio) hydroquinone The describeddeveloper inhibitor releasing compounds are especially suitableaccording to the invention in an element which is photosensitive andthermosensitive, especially a photographic element which is suitable forprocessing with heat. Photographic and thermosensitive elements whichare suitable for dry processing with heat can provide a developed imageby physical development, such as described in U.S. Patent 3,457,075 ofMorgan et al. issued July 22, 1969. Other elements of this type aredescribed, for example, in U.S. Patent 3,429,706 of Shepard et al.issued Feb. 25, 1969 and U.S. Patent 3,152,904 of Sorensen et al. issuedOct. 13, 1964. In elements, as described, typically a support isprovided with a light-stable organic silver salt oxidizing agent, anorganic reducing agent, and photographic silver salt, especially silverhalide, which provides a photographic and heat-sensitive element. Avisible image on the photographic and thermosensitive element can beproduced within a few seconds after exposure by heating the element tomoderately elevated temperatures.

Accordingly, one embodiment of the invention is a photographic andthermosensitive element, comprising a support,

(a) a silver halide development inhibitor releasing compound, and

(b) a stable source of silver for physical development of a latent imagein a photographic element.

The silver halide development inhibitor releasing compound is typicallya developer inhibitor releasing coupler or developer inhibitor releasingsilver halide developing agent, as described.

The described silver halide development inhibitor releasing compoundscan be employed in a photographic and thermosensitive element containinga silver-dye complex, a silver halide developing agent, a source ofsilver for physical development, as described, especially silverbehenate or silver stearate and a binder, especially polyvinylbutyral.Suitable silver-dye complexes are set out in U.S. Patent 3,446,619 ofGilman et al. issued May 27, 1969. The silver-dye complex is a reactionproduct of silver ions, e.g. silver nitrate in aqueous solution, with aspectral sensitizing dye which upon exposure to radiation forms activesites for physical development. Typical sensitizing dyes includecyanines, merocyanines, oxonols, hemicyanines, hemioxonols, styrlys andbenzylidenes. A typical photographic and thermosensitive elementcontaining such a silver-dye complex comprises a support having a layercontaining a silver-merocyanine dye complex, silver behenate,hydroquinone, a binder, such as cellulose acetate, polyvinyl acetate orpolyvinylbutyral and a developer inhibitor releasing compound, asdescribed. The photographic and thermosensitive element can contain astabilizing agent such as an organic acid stabilizing agent, e.g.phthalic acid, salicylic acid or benzoic acid.

The described elements can comprise a silver salt of an organic acid, asan oxidizing agent. The silver salt of the organic acid should beresistant to darkening under illumination to prevent undesireddeterioration of a developed image. An especially suitable class ofsilver salts of organic acids is represented by the water insolublesilver salts of long-chain fatty acids which are stable to light.Compounds which are suitable silver salts include silver behenate,silver stearate, silver oleate, silver laurate, silver hydroxystearate,silver caprate, silver myristate, and silver palmitate. Other suitableoxidizing agents are silver S-nitrosalicylaldoxime, silverS-chlorosalicylaldoxime, silver-benzoate, silver-phthalazinone,silver-benzotriazole, silver-saccharin,silver-4'-n-octadecyloxydiphenyl-4-carboxylic acid,silver-ortho-aminobenzoate, silver acetamidobenzoate, silver furoate,silver camphorate, silver p-phenylbenzoate, silver phenyl acetate,silver salicylate, silver meta-nitrobenzoate, silver butyrate, silverterephthalate, silver phthalate, silver acetate, and silver acidphthalate. Oxidizing agents which are not silver salts can be employedif desired, such as zinc oxide, gold stearate, mercuric behenate, auricbehenate and the like.

An organic reducing agent is employed in the practice of the inventionto provide a desired developed image. Such reducing agents are typicallysilver halide developing agents. Suitable silver halide developingagents or organic reducing agents include, for example,polyhydroxybenzenes such as hydroquinone developing agents, e.g.hydroquinone, alkyl-substituted hydroquinones as exemplified by tertiarybutyl hydroquinone, methyl hvdroquinone, 2,5-dimethyl hydroquinone and2,6-dimethyl hydroquinone; catechols and pyrogallol; halo-substitutedhydroquinones such as chlorohydroquinone or dichlorohydroquinone;alkoxy-substituted hydroquinones such as methoxy hydroquinone or ethoxyhydroquinone; methylhydroxy naphthalene; phenylenediamine developingagents; methylgalate; aminophenol developing agents, such as2,4-diaminophenols and methylaminophenols; ascorbic acid developingagents such as ascorbic acid, ascorbic acid ketals and ascorbic acidderivatives such as those described in U.S. Pat. 3,337,342 of Greenissued Aug. 22, 1967; hydroxylarnine developing agent such asN,N-di(2-ethoxyethyl) hydroxylamine; 3-pyrazolidone developing agentssuch as 1-phenyl-3-pyrazolidone and 4methyl-4-hydroxymethyl-1-phenyl-3-pyrazolidone including those describedin British Pat. 930,572 published July 3, 1963; hydroxytetronic acid,and hydroxytetronimide developing agents; reductone developing agentssuch as anhydro dihydro piperidino hexose reductone or anhydro dihydropyrrolidino hexose reductone; and the like.

The described element contains a photographic salt, especially aphotographic silver salt. Suitable photographic silver salts includesilver chloride, silver bromide, silver bromoiodide, silverchlorobromoiodide or mixtures thereof. The photographic silver halidecan be coarse or fine-grain, very fine grain emulsions being especiallyuseful. The emulsion containing the photographic silver halide can beprepared by any of the well-known procedures in the photographic art,such as single-jet emulsions, double-jet emulsions, such as Lippmannemulsions, ammoniacal emulsions, thiocyanate or thioether ripenedemulsions, such as those described in U.S. Pat.

2,222,264 of Nietz et al. issued Nov. 14, 1940; U.S. Pat.

3,320,069 of Illingsworth issued May 15, 1967 and U.S. Pat. 3,271,157 ofMcBride issued Sept. 6, 1966. Surface image silver halide emulsions canbe used or internal image silver halide emulsions such as thosedescribed in U.S. Pat. 2,592,250 of Davey et al. issued Apr. 8, 1952;U.S. 3,206,313 of Porter et al. issued Sept. 14, 1965; U.S. Pat.3,367,778 of Berriman et al. issued Feb. 6, 1968; and U.S. Pat.3,447,927 of Bacon et al. issued June 3, 1969. If desired, mixtures ofsurface and internal image silver halide emulsions can be used asdescribed in U.S. Pat. 2,996,382 of Luckey et al. issued Apr. 15, 1961.Negative type emulsions can be used or direct positive silver halideemulsions such as those described in U.S. Pat. 2,184,013 of Leermakersissued Dec. 19, 1939; U.S. Pat. 2,541,472 of Kendall et al. issued Feb.13, 1951; U.S. Pat. 3,367,778 of Berriman et al. issued Feb. 6, 1968;British Pat. 723,,019; French Pat. 1,520,821; U.S. Pat. 2,563,785 ofIves issued Aug. 7, 1951; U.S. Pat. 2,456,953 of Knott et al. issuedDec. 21, 1968; and U.S. Pat. 2,861,885 of Land issued Nov. 25, 1958. Thesilver halide emulsion can be a regular grain emulsion such as describedin Klein and Moisar, Journal of Photographic Science, vol. 12, No. 5,September-October (1964) pp. 242-251.

The silver halide emulsions employed in the practice of the inventioncan be unwashed or washed to remove soluble salts. In the latter casethe soluble salts can be removed by chill setting and bleaching or theemulsion can be coagulation washed.

The silver halide employed in the practice of the invention can besensitized with chemical sensitizers, such as with reducing agents;silver, selenium, or tellurium compounds; gold, platinum, or palladiumcompounds; or combinations of these. Suitable procedures are described,for example, in U.S. Pat. 1,623,499 of Shepard issued Apr. 5, 1927; U.S.Pat. 2,399,083 of Waller et al. issued Apr. 23, 1946; U.S. Pat.3,297,447 of McVeigh issued Jan. 10, 1967; and U.S. Pat. 3,297,446 ofDunn issued Jan. 10, 1967.

Photographic silver halide emulsions employed in the practice of theinvention can be protected against the production of fog and can bestabilized against loss of sensitivity during keeping. Suitableantifoggants and stabilizers, e.g. used alone or in combination include,for example, thiazolium salts; azaindenes; mercury salts as described,for example, in U.S. Patent 2,728,663 of Allen et al. issued Dec. 27,1955; urazoles; sulfocatechols; oximes described, for example in BritishPatent 623,448; nitron; nitroindazoles; polyvalent metal saltsdescribed, for example, in U.S. Patent 2,839,405 of Jones issued June17, 1958; platinum, palladium and gold salts described, for example, inU.S. Patent 2,566,263 of Trivelli et al. issued Aug. 28, 1951 and U.S.Patent 2,597,915 of Yutzy et al. issued May 27, 1952.

A photographic and thermosensitive element and emulsions described andused in the practice of the invention can contain various colloids aloneor in combination as vehicles, biding agents and in various layers.Suitable materials are typically hydrophobic but hydrophilic materialscan also be employed. They are transparent or translucent and includeboth naturally-occurring substances such as proteins, for example,gelatin, gelatin derivatives, cellulose derivatives, polysaccharidessuch as dextran, gum arabic and the like; and synthetic polymericsubstances such as water-soluble polvinyl compounds like poly(vinylpyrrolidone), acrylamide polymers and the like. Other syntheticpolymeric compounds which can be employed include dispersed vinylcompounds such as in latex form and particularly those which increasedimensional stability of photographic materials. Suitable syntheticpolymers include those described in U.S. Patent 3,142,586 of Nottorfissued July 28, 1964; U.S. Patent 3,193,386 of White issued July 6,1955; U.S. Patent 3,062,674 of Houck et al. issued Nov. 6, 1962; U.S.Patent 3,220,844 of Houck et al. issued Nov. 30, 1965; U.S. Patent3,287,289 of Ream et al. issued Nov. 22, 1966; and U.S. Patent 3,411,911of Dykstra issued Nov. 19, 1968. Effective polymers include waterinsoluble polymers of alkyl acrylates and methacrylates, acrylic acid,sulfoalkyl acrylates or methacrylates, and those which havecross-linking sites which facilitate hardening or curing as well asthose having recurring sulfobetaine units as described in CanadianPatent 774,054. Preferred high molecular weight materials and resinsinclude polyvinyl butyral, cellulose acetate butyrate, polymethylmethacrylate, poly(vinyl pyrrolidone) ethyl cellulose, polystyrene,polyvinyl chloride, chlorinated rubber, polyisobutylene,butadiene-styrene copolymers, vinyl chloride-vinyl acetate copolymers,copolymers of vinyl acetate, vinyl chloride and maleic acid, polyvinylalcohol, and high molecular weight ethylene oxide polymers.

The photographic and thermosensitive layers and other layers of anelement employed in the practice of the invention and described hereincan be coated on a wide variety of supports. Typical supports includecellulose nitrate film, cellulose ester film, poly(vinylacetal) film,polystyrene film, poly(ethylene terephthalate) film, polycarbonate filmand related films or resinous materials, as Well as glass, paper, metaland the like. Typically a flexible support is employed, especially apaper support which can be partially acetylated or coated with barytaand/or an alpha olefin polymer, particularly a polymer of an alphaolefin containing 2 to 10 carbon atoms such as polyethylene,polypropylene, ethylene-butene copolymers and the like.

The photosensitive and thermosensitive and other hardenable layers of anelement used in the practice of this invention can be hardened byvarious organic or inorganic hardeners, alone or in combination, such asaldehydes, and blocked aldehydes, ketones, carboxylic and carbonic acidderivatives, sulfonate esters, sulfonyl halides and vinyl sulfonylethers, active halogen compounds, epoxy compounds, aziridines, activeolefins, isocyanates, carbodiimides, mixedfunction hardeners andpolymeric hardeners such as oxidized polysaccharides like dialdehydestarch and oxyguargum and the like.

The photoghaphic and thermosensitive elements used in the practice ofthe invention can contain antistatic or conducting layers. Such layerscan comprise soluble salts such as chlorides, nitrates and the like,evaporated metal layers, ionic polymers such as those described in U.S.Patent 2,861,056 of Minsk issued Nov. 18, 1958 and U.S. Patent 3,206,312of Sterman et al. issued Sept. 14, 1965 or insoluble inorganic saltssuch as those described in U.S. Patent 3,428,451 of Trevoy issued Feb.18, 1960. The photographic and thermosensitive elements can also containantihalation materials nad antihalation dyes.

The photographic and thermosensitive layers or other layers employed inthe practice of the invention can contain plasticizers and lubricants.Suitable plasticizers and lubricants include, for example, polyalcoholssuch as glycerin and diols described, for example, in U.S. Patent2,960,404 of Milton et al. issued Nov. 1, 1966; fatty acids or esterssuch as those described in U.S. Patent 2,588,765 of Robijns issued Mar.11, 1952; U.S. Patent 3,121,060 of Duane issued Feb. 11, 1964; andsilicone resins such a those described in British 955,061.

The photographic and thermosensitive layers or other layers empoyed inthe practice of the invention can contain surfactants such as saponin;anionic compounds such as alkyl aryl sulfonates described, for example,in U.S. Patent 2,600,831 of Baldsiefen issued June 17, 1962; amphotericcompounds such as those described in U.S. Patent 3,133,816 of Ben-Ezraissued May 19, 1964; and adducts of glycidol and an alkyl phenol such asthose described in British Patent 1,022,878.

If desired, the photographic and thermosensitive elements employed inthe practice of the invention can contain matting agents such as starch,titanium dioxide, zinc oxide, silica, polymeric beads including beadsdescribed, for example, in U.S. Patent 2,922,101 of Jelley et al. issuedJuly 11, 1961 and U.S. Patent 2,701,245 of Lynn issued Feb. 1, 1955.

The photographic and thermosensitive elements employed in the practiceof the invention can contain brightening agents including stilbenes,triazines, oxazoles, and coumarin brightening agents. Water-solublebrightening agents can be used such as those described in German Pat.072,067 and U.S. Patent 2,933,390 of McFall et al. issued Apr. 19, 1960or dispersions of brighteners can be used such as those described inGerman Patent 1,150,274; U.S. Patent 3,406,070 of Oetiker et al. issuedOct. 15, 1968 and French Patent 1,530,244.

The various layers including the photographic and thermosensitive layersof an element employed in the practice of the invention can containlight-absorbing materials and filter dyes such as those described inU.S. Patent 3,253,921 of Sawdey issued May 31, 1966; U.S. Patent2,274,782 of Gaspar issued Mar. 3, 1942; U.S. Patent 2,527,583 ofSilberstein et al. issued Oct. 31, 1950; and U.S. Patent 2,956,879 ofVanCampen issued Oct. 18, 1960. If desired, the dyes can be mordanted,for example, as described in U.S. Patent 3,282,699 of Jones et al.issued Nov. 1, 1966.

The photographic and thermosensitive layers used in the practice of theinvention can be coated by various coating procedures including dipcoating, airknife coating, curtain coating or extrusion coating usinghoppers such as described in U.S. Patent 2,681,294 of Beguin issued June15, 1954. If desired, two or more layers can be coated simultaneouslysuch as by the procedures described in U.S. Patent 2,761,791 of Russellissued Sept. 4, 1956 and British 837,095.

If desired, the photographic silver halide can be prepared in situ inthe photographic and thermosensitive coatings of an element employed inthe practice of the invention. Such a method is described, for example,in U.S. Patent 3,457,075 of Morgan et al. issued July 22, 1969. Forexample, a dilute solution of a halogen acid such as hydrochloric acidcan be applied to the surface of a thin coating containing an organicsilver salt, such as silver behenate, on a suitable substrate followedby removal of the solvent if desired. Silver halide is thus 10 formed insitu throughout the surface of the coating of the organic silver salt.

The photographic silver halide can be prepared on the oxidizing agentsuch as silver behenate or silver stearate or other organic silver saltprior to application of the silver halide on the support employed. Thisis also described in U.S. Patent 3,457,075 of Morgan et al. issued July22, 1969, for example, a halogen acid such as hydrochloric acid orhydrobromic acid can be mixed with an organic silver salt in a suitablereaction medium. A halide salt more soluble than the organic silver saltcan be added to a suspension of the organic silver salt to form thesilver halide. A suitable reaction medium includes water or othersolutions which do not interfere with the reaction.

Stability to light exposure is increased by employing highly purifiedmaterials; for example; freedom from halides and sulfides increasestability to light exposure. The use of highly purified silver behenatecan, for example, reduced light sensitivity of an element according tothe invention.

Accordingly one embodiment of the invention is in a photographic andthermosensitive element comprising a support, a photographic silversalt, a source of silver for physical development of the silver salt, anorganic reducing agent, and a binder; the improvement comprising asilver halide development inhibitor releasing compound which has theproperties of releasing a silver halide development inhibitor at aboveabout 70 C. As described, the stable source of silver for physicaldevelopment is typically a silver salt of an organic acid. The organicreducing agent can be a silver halide developing agent, as described.

When a so-called developer inhibitor releasing coupler is employed asthe silver halide development inhibitor releasing compound as described,it is surprisingly found that the sensitivity of the photographicelement to radiation outside the inherent blue region of the spectrum,such as sensitivity to tungsten light, is improved even without the useof a sensitizing dye. However spectral sensitizing dyes can be usedconveniently to confer additional sensi tivity to the light-sensitivesilver halide employed in the practice of the invention. For instance,additional spectral sensitization can be obtained by treating the silverhalide With a solution of a sensitizing dye in an organic solvent or thedye can be added in the form of a dispersion as described in BritishPatent 1,154,781. For optimum results the dye can either be added to theemulsion as a final step or at some earlier stage.

Sensitizing dyes useful in sensitizing silver halide emulsions aredescribed, for example, in U.S. Patent 2,526,632 of Brooker et al.issued Oct. 24, 1950; U.S. Patent 2,503,776 of Sprague issued Apr. 11,1950; U.S. Patent 2,493,748 of Brooker et al. issued Jan. 10, 1950 andU.S. Patent 3,384,486 of Taber et al. issued May 21, 1968. Spectralsensitizers which can be used include the cyanines, merocyanines,complex (trinuclear or tetranuclear) merocyanines, complex (trinuclearor tetranuclear) cyanines, holopolar cyanines, styryls, hemicyaninessuch as enamine, hemicyanines, oxonols and hemioxonols. Dyes of thecyanine classes can contain such basic nuclei as the thiazolines,oxazolines, pyrrolines, pyridines, oxazoles, thiazoles, selenazoles, andimidazoles. Such nuclei can contain alkyl, alkylene, hydroxyalkyl,sulfoalkyl, carboxyalkyl, aminoalkyl, and enamine groups that can befused to carbocyclic or heterocyclic ring systems either unsubstitutedor substituted with halogen, phenyl, alkyl, haloalkyl, cyano, or alkoxygroups. The dyes can be symmetrical or unsymmetrical and can containalkyl, phenyl, enamine or heterocyclic substituents on the methine orpolymethine chain.

The mercocyanine dyes can contain the basic nuclei described as well asacid nuclei such as thiohydantoins, rhodanines, oxazolidenediones,thiazolidenediones, barbituric acids, thiazolineones, and malononitrile.These acid nuclei can be substituted with alkyl, alkylene, phenyl,carboxyalkyl, sulfoalkyl, hydroxyalkyl, alkoxyalkyl, alkylamino groups,or heterocyclic nuclei. Combinations of these dyes can be used, ifdesired. In addition supersensitizing addenda which do not absorbvisible light may be included such as, for instance, ascorbic acidderivatives, azaindenes, cadmium salts, and organic sulfonic acid asdescribed in U.S. Patent 2,933,390 of McFall et al. issued Apr. 19, 1960and U.S. Patent 2,937,089 of Jones et al. issued May 17, 1960-.

The sensitizing dyes and other addenda used in the practice of theinvention can be added from water solutions or suitable organic solventsolutions can be used. The compounds can be added using variousprocedures including, for example, those described in U.S. Patent2,912,343 of Collins et al. issued Nov. 10, 1959; U.S. Patent 3,342,605of McCrossen et al. issued Sept. 19, 1967; U.S. Patent 2,996,287 ofAudran issued Aug. 15, 1961; and U.S. Patent 3,425,835 of Johnson et al.issued Feb. 4, 1969.

A range of concentration of dye can be employed in the practice of theinvention. The desired concentration will be influenced by the desiredspectral sensitivity, other components in the system, the desired image,processing conditions and the like. Typically a concentration of thedescribed sensitizing dye is about 0.05 to about 1 milligram per squarefoot of the described photographic and thermosensitive element, usuallyabout 0.1 milligram per square foot of dye being employed.

It is often advantageous to employ a so-called toner in the describedphotographic and thermosensitive elements. Various toners can beemployed for this purpose. Typically a heterocyclic organic toning agentcontaining at least two hetero atoms in the heterocyclic ring of whichat least one is a nitrogen atom is employed. These are described, forexample, in U.S. Patent 3,080,254 of Grant issued Mar. 5, 1963. Suitabletoners include, for example, phthalazinone, phthalic anhydride, Z-acetylphthalazinone, 2-phthalyl phthalazinone. Other suitable toners aredescribed, for example, in U.S. Patent 3,446,648 of Workman issued May27, 1969.

Accordingly another embodiment of the invention is a photographic andthermosensitive element, as described,

(a) wherein the development inhibitor releasing compound is a couplerhaving a tetrazolylthio moiety, (b) the source of silver for physicaldevelopment is silver behenate or silver stearate,

(c) the photographic silver salt is photographic silver halide,

(d) the binder is polyvinyl butyral,

(e) the reducing agent is a phenolic reducing agent, and

also

(f) comprising a toner.

For example, the photographic and thermosensitive element as describedcan comprise,

(a) polyvinyl butyral binder,

(b) silver behenate,

(c) a phenolic reducing agent,

((1) photographic silver halide,

(e) a phthalazinone toner,

(f) l-hydroxy-4-(l phen'yl 5tetrazolylthio)-2-(2'-ntetradecyloxy)-naphthanilide, and

(g) a. sensitizing dye.

Another embodiment of the invention is a photographic andthermosensitive emulsion comprising (a) a silver halide developmentinhibitor releasing compound as described, (b) a stable source of silverfor physical development, and (c) photographic silver salt, especiallyphotographic silver halide. The photographic and thermosensitiveemulsion can comprise, for instance,

(a) a silver halide development inhibitor releasing compound which hasthe property of releasing a silver halide development inhibitor at aboveabout 70 C.,

12 especially a developer inhibitor releasing coupler as described, (b)silver behenate, (c) photographic silver halide, (d) a phenolic reducingagent, (e) polyvinyl butyral, and (f) a sensitizing dye.

After exposure of the described photographic and thermosensitive elementthe resulting latent image is developed and the developed imagestabilized merely by heating the element. Accordingly another embodimentof the invention is: in a process of developing a latent image in aphotographic and thermosensitive element and stabilizing the resultingdevelopment image with heat, the improvement comprising heating anexposed photographic and thermosensitive element comprising (a) aphotographic component,

(b) a source of metal for physical development of the photographiccomponent,

(c) a development inhibitor releasing compound which has the property ofreleasing a silver halide development inhibitor at above about C., and

(d) a reducing agent,

to 70 C. to 250 C. A temperature range of about C. to about C. issuitable for developing and stabilizing a desired image. By increasingor decreasing the length of time of heating a higher or lowertemperature within the described range can be employed. A developed andstable image is typically produced within a few seconds such as about 1second to about 60 seconds.

Processing is usually carried out under ambient conditions oftemperature, pressure and humidity. Temperatures, pressures, andhumidity outside normal atmospheric conditions can be employed ifdesired; however, normal atmospheric conditions are preferred.

In some cases, if desired, an element can be prepared wherein thedescribed silver halide can be in one layer and other components inother layers. For example, an element according to the invention cancomprise a support, a layer containing photographic silver halide, and alayer comprising a so-called processing composition comprising (a) asilver salt of an organic acid,

(b) a silver halide developing agent, and

(c) a silver halide development inhibitor releasing compound, asdescribed, which has the property of releasing a silver halidedevelopment inhibitor at above about 70 C.

A processing composition of this type is a photographic processingcomposition comprising (a) silver behenate,

(b) a silver halide developing agent, and

(c) l-hydroxy-4-(1 phenyl 5tetrazolylthio)-2-(2'-ntetradecyloxy)-naphthanilide.

Typically a polyvinyl but'yral binder is employed with this procesisngcomposition.

Various means can be employed in providing the necessary heating of thedescribed photographic and thermosensitive elements. The heating meanscan be a simple hot plate, iron or the like.

Other addenda known to be useful in photographic and thermosensitiveelements of this type such as described in British Patent 1,161,777published Aug. 20, 1969 and U.S. Patent 3,152,904 of Sorensen et al.issued Oct. 13, 1964 can be employed in the practice of the invention.

The following examples are included for a further understanding of theinvention.

EXAMPLE 1 This illustrates the invention. A photographic element isprepared as follows:

13 A coating composition is prepared by mixing the following components:

polyvinyl butyral-10.0 g.

silver behenate (about 60% pure, other components not identified)-28.0g.

methanol133.0 ml.

acetonefi-133.0 ml.

toluene133.0 ml.

After mixing, the following solutions are added to the resultingdispersion:

Ml. Methanol containing 2% by weight salicylic acid 40.0 Acetonecontaining 2.5% by weight 1-hydroxy-4- (laphenyltetrazolylthio)-2-(2'-n-tetradecyloxy)-naphthanilide 400.0 Methanolcontaining by weight 4-phenylcatechol 40.0

The composition is mixed and then coated on a waterresistant papersupport at 5 milliliters per square foot of support and dried providinga photographic and thermosensitive element containing 30 milligrams persquare foot of silver.

The photographic element is exposed sensitometrically with ultravioletlight for 5 seconds. The resulting latent image is developed by holdingthe photographic element in contact with a metal block at 85 C. for 5seconds.

A developed image is produced. The developed image is held in roomfluorescent light for 14 days at about 20 C. and during that periodshows no visible change. The visible image is accordingly consideredstable. The maximum density of the image is 1.80 and the minimum densityis 0.20 with very low background stain.

EXAMPLE 2 This is a comparative example.

The procedure set out in Example 1 is repeated with the exception thatthe 1 hydroxy 4 (1-phenyl-5-tetrazolylthio) 2 (2'n-tetradecyloxy)-naphthanilide is omitted from the describedphotographic and thermosensitive element.

The resulting developed image is held in room fluorescent light for 14days. During the first 24 hours the background rapidly darkens until themaximum density about equals the minimum density of the image.

This demonstrates the undesired instability in the absence of adevelopment inhibitor releasing compound according to the invention.

EXAMPLE 3 The procedure set out in Example 1 is repeated with theexception that 0.1 milligram per square foot of support of a sensitizingdye which is 1-carboxymethyl-5-[(.3- ethyl 2(3H) benzoxazolylidene)ethylidene] 3- phenyl 2 thiohydantoin is employed in the describedphotographic and thermosensitive element.

The photographic element is exposed sensitometrically with tungstenlight (120 watt light bulb in a contact printer) for 5 seconds. Theresulting latent image is developed by holding the photographic elementin contact with a metal block at 85 C. for 30 seconds.

A developed image is produced. The developed image is held in roomfluorescent light for 14 days at about 20 C. and during that periodshows novisible change. This developed image is considered stable. Themaximum density of the image is 1.80 and the minimum density is 0.20with very low background stain.

EXAMPLE 4 This is a comparative example.

The procedure set out in Example 1 is repeated with the exception thatan equirnolar concentration of 1- phenyl 5 mercaptotetrazole is employedin place of 1 hydroxy 4 (1 phenyl 5 tetrazolylthio)-2-(2'-n-tetradecyloxy)-naphthanilide.

This provides an image which is barely visible and having a graybackground.

This demonstrates that 1 phenyl-S-mercaptotetrazole causes undesireddesensitization in a photographic element as described.

EXAMPLE 5 This illustrates the invention employing a developer inhibitorreleasing developing agent.

A photographic and thermosensitive element is prepared as follows:

polyvinyl butyral10.0 g. silver benhenate-28.0 g. acetone-toluene (1:1by volume)400.0 ml.

The following is added to 10 milliliters of the resulting dispersion:

Ammonium iodide (0.6% by Weight acetone solution) 2.0

2 mercapto 5 phenyl 1,3,4 oxadiazole (1.0%

by weight acetone solution) 5.0

1 hydroxy 4 (1 phenyl 5 tetrazolylthio)- 2(2'-n-tetradecyloxy)-naphthanilide (2% by weight acetone solution) 20.0

Trimethyl (1 phenyl 5 tetrazolylthio) hydroquinone (2% by weight acetonesolution) 15.0

The ammonium iodide reacts with the silver behenate to to formphotographic silver iodide. The resulting composition is coated on apaper support at 30 to 75 milligrams of silver per square foot ofsupport to produce a photographic and thermosensitive element. Thiselement is exposed to ultraviolet light for 5 to 10 seconds. Theresulting latent image is developed by holding the photographic elementin contact with a metal block at C. for 5 seconds.

A developed image is produced. The developed image is held in roomfluorescent light, at about 20 C., and after 15 months the image has ablack tone with a light yellow background. This demonstrates thestability of an image according to the invention.

EXAMPLE 6 The procedure set out in Example 5 is repeated with theexception that a polyethylene terephthalate film support is employed inplace of a paper support.

The resulting developed image is black. The image is held in roomfluorescent light at about 20 C., and after 15 months the image has abrown-black tone and a yellowbrown background.

EXAMPLE 7 This illustrates the invention.

A photographic and thermosensitive element is prepared as follows:

A coating composition is prepared by mixing the following components:

polyvinyl butyrall0.0 g.

silver behenate (about 60% pure, other components not identified)28.0 g.

acetone-toluene (1:1 by volume)--400.0 ml.

It is believed that the phthalic acid and benzotriazole function astoning agents. The resulting composition is coated on a polyethylenecoated paper support at 30 to 75 milligrams of silver per square foot ofsupport to produce a photographic and thermosensitive element. Thiselement is exposed to ultraviolet light for to seconds. The resultinglatent image is developed by holding the photographic element in contactwith a metal block at 85 C. for 5 seconds.

The resulting photographic image is dark brown and has a light brownbackground.

EXAMPLE 8 Similar results are obtained as in Example 1 also employingphthalazinone, as a toner, in the described element.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

I claim:

1. A photothermographic element comprising a support having thereon (a)photographic silver salt,

(b) a source of silver for physical development which is a silver saltof an organic acid,

(c) an organic reducing agent,

(d) a binder, and

(e) a silver halide development inhibitor releasing compound which is acompound having a tetrazolylthio moiety which is released from saidinhibitor releasing compound at above about 70 C.

2. A photothermographic element as in claim 1 wherein said organicreducing agent is a silver halide developing agent.

3. A photothermographic element as in claim 1 comprising a sensitizingdye.

4. A photothermographic element as in claim 1 wherein said developmentinhibitor releasing compound is a coupler having a tetrazolylthiomoiety.

5. A photothermographic element as in claim 1 wherein said developmentinhibitor releasing compound is 1- hydroxy 4(1-phenyl-5-tetrazolylthio)-2-(2-n-tetradecyloxy -naphthanilide.

6. A photothermographic element as in claim 1 comprising a toner.

7. A photothermographic element comprising a support having thereon:

(a) polyvinyl butyral binder,

(b) silver behenate,

(c) a phenolic reducing agent,

(d) photographic silver halide,

(e) a phthalazinone toner,

(f) l hydroxy4-(1-phenyl-5-tetrazolylthio)-2-(2'-ntetradecyloxy)-naphthanilide, and

(g) a sensitizing dye.

8. A photothermographic composition comprising (a) a silver halidedevelopment inhibitor releasing compound which is a compound having atetrazolylthio moiety which is released from said compound at aboveabout 70 C.,

(b) silver behenate,

(c) photographic silver halide,

(d) a phenolic reducing agent,

(e) polyvinyl butyral, and

(f) a sensitizing dye.

9. A photographic processing composition comprising (a) silver behenate,(b) a silver halide developing agent, and (c) 1-hydroxy-4-(1-phenyl-5-tetrazolylthio)-2-(2-ntetradecyloxy)-naphthanilide.

10. A photographic processing composition as in claim 9 comprising apolyvinyl butyral binder.

11. A photothermographic element comprising a support having thereonphotographic silver halide,

(b) a source of silver for physical development which is a compoundselected from the group consisting of silver behenate and silverstearate,

(c) a phenolic reducing agent,

(d) a polymeric binder, and

(e) a silver halide development inhibitor releasing compound which is acoupler having a tetrazolylthio moiety which is released from saidcoupler at above about 70 C.,

(t) a toner, and

(g) a sensitizing dye.

12. A photothermographic composition comprising (a) photographic silversalt,

(b) a source of silver for physical development which is a silver saltof an organic acid, and

(c) a silver halide development inhibitor releasing compound which is acompound having a tetrazolylthiomoiety which is released from saidinhibitor releasing compound at above about 70 C.

13. A process of developing a latent image in a photothermographicelement comprising a support having thereon (a) a photographic silversalt,

(b) a source of silver for physical development which is a silver saltof an organic acid,

(c) a binder,

(d) an organic reducing agent and a silver halide development inhibitorreleasing compound which is a compound having a tetrazolylthio moietywhich is released from said inhibitor releasing compound at above about70 C., and stabilizing the resulting developed image comprising heatingsaid element from about 70 C. to about 250 C.

14. A process of developing a latent image in a photothermographicelement comprising a support having thereon (a) photographic silverhalide,

(b) silver behenate,

(c) polyvinyl butyral binder,

(d) a phenolic reducing agent,

(e) 1 hydroxy-4-(l-phenyl-5-tetrazolylthio)-2-(2'-tetradecyloxy-naphthanilide,

(f) a phthalazinone toner, and

(g) a sensitizing dye, and stabilizing the resulting developed imagecomprising heating said element from about 70 C. to about 250 C.

15. A photographic processing composition comprising (a) a silver saltof an organic acid,

(b) a silver halide developing agent and (c) a silver halide developmentinhibitor releasing compound which is a compound having a tetrazolylthiomoiety which is released from said inhibitor releasing compound at aboveabout 70 C.

References Cited UNITED STATES PATENTS Re. 26,719 11/1969 Sorensen 96-503,180,731 4/1965 Roman 961 14.1 3,227,554 l/1966 Barr 963 3,379,5294/1968 Porter 96-36 3,457,075 7/1969 Morgan 96-114.1 3,429,706 2/1969Shepard 11734 NORMAN G. TORCHIN, Primary Examiner J. R. HIGHTOWER,Assistant Examiner US. Cl. X.R. 9666; 1l736.7

mg TJNTTTD STATES PATENT oTTTeT CERTTTTCA'TE CF CCRRECHCN Patent No. n sDated October 97 Inventofls) ary J. Youngquist It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 2A, "developmnet" should read ---developmeht-- Column 6,line 33, "styrlys" should read ---styryls-. I

Column 7 Line 50, "723,,019

line 11 "agent" should read ---agehts-.

"' shouldread ---723',o19---.

- Column 8, line 16, "hiding" should read ---bihding--. Line 73,"photoghaphic" should read ---photographic---.,

Column 9, line 6, "1960" should read ---l969-. Line 8 "had" shouldread-and---. Line do, "072,067" should read ---972,-O 67-.

- Columh 10, line 72, "mercocyanine" should read --merocyahine. 1

Column 12 line 1%, "development" should read --developed-.

Column 11L, line 13, "benhenate" should read ---behehate---.

Signed and sealed this 29th day of May 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissionerof Patents

